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I just modified my Iscorama 36 for close focus


richg101
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Wow! This is really astonishing!

However I don't dare to join the club. I am even often anxious to take my Isco outside. 

Maybe the reason therefore is that it is old new... If it would have some signs of use it would be

a lot easier. 

 

QuickHitRecord: Maybe you can sell me your "Xume-Diopter-Clamps" for my nearsighted lens?  :)

 

rudolf

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i dont want to take mine apart again. anyway I dont think images will help. you need to see inside first hand. it's very simple* once you get inside and the main optical elements dont need to be touched.

1. set the iscorama to infinity

2. remove the plastic ring around the front element with 'iscorama 36 - 1.5 etc' printed on it,

3. unscrew the 4x screws with the right size precision screwdriver. - store safely!

4. the plastic housing will lift off easily (the plastic part with the focus scale printed on it).

5. examine the inside of the plastic housing - you will see two stoppers - one of which needs to be shaved away with a dremel multi. you need to actually look at the inside to understand what is going on. it's simple once you see inside. one of the stoppers is for infinity and one is for minimum focus. it becomes apparent which is which once you are inside.


6. clean the plastic housing in cold water to remove the grinded plastic dust and then dry properly.

7. re assemble as before.

NOTE:- after the modification take care not to turn more than 1 whole turn or the front element will untwist completely. with mine I make sure not to turn the focus ring past the infinity mark.

*simplicity is subjective I suppose. if you are not used to handling precision screwdrivers, or using a dremel grinding tool to grind soft plastic, I don't suggest you try this.

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Removing the plastic ring is the part that worries me.  Are we talking about the flat ring with the iscorama label printed on it only (recessed into the 72mm threaded lip)?  Or do you grip the focus ring on the outside and unscrew it like the lid of a jar?  (It seems to be one solid piece).  I'm mostly concerned about applying too much pressure and breaking something.

 

The rest of the instructions seem straightforward.

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Removing the plastic ring is the part that worries me. Are we talking about the flat ring with the iscorama label printed on it only (recessed into the 72mm threaded lip)? Or do you grip the focus ring on the outside and unscrew it like the lid of a jar? (It seems to be one solid piece). I'm mostly concerned about applying too much pressure and breaking something.

The rest of the instructions seem straightforward.


Not the jar way - the focus ring part with the ribbing and printed focus scale is a solid part. you need to remove the the ring (with the "isco-gottingen iscorama anamorphot 1.5 - 36" printed on it) on the inside of the 72mm thread. as you twist it, it unthreads from the same thread as you would attach diopters. you cannot physically grasp the ring due to it being recessed into the thread so you need to press against it while trying to twist it at the same time - in the same direction you would untwist a diopter from the 72mm thread.

QuickHitRecord had to use some rubber gloves in order to allow him to spin the ring - otherwise there isnt enough friction. mine came away slowly by hand, but it would have been quicker if I had used some rubber gloves. Make sure you mask off the front element with some masking tape to be sure you dont scratch the element.
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I have an early [mint] plastic Iscorama that came with the Nikon mount 50mm f2.8 taking lens [which I believe is different from the 36] - does anyone know if this mod would be the same?

 

 

I am unsure.  I would suggest reading the wiki page to determine if the front 'anamorphot' part is the same as a typical '36'.  I doubt there is much change in construction on the actual anamorphot part - you are not affecting any part of the taking lens (which I believe is the only differece between yours and a normal 36.)

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Is this the known slacken the screws? mod

Does it show softer focus at F2?



If this method involves what I think it does, 'slackening the screws' will only allow you to change the focus range from original 'infinity to 6feet' and change it to a 'macro only'. when I say macro only, you will be able to adjust so the focus range is changed to the minimum of about 3.5ft to around 8-10ft maximum. the two stoppers on the inside of the plastic focus ring are the determining scale - they allow 1/2 a turn as standard. in order to get 3.5ft-infinity you need to be able to rotate the focus ring 1 whole turn from the point of infinity. - to allow this the 'minimum focus point stopper' needs to be grinded off the inside of the plastic focus ring.
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Not the jar way - the focus ring part with the ribbing and printed focus scale is a solid part. you need to remove the the ring (with the "isco-gottingen iscorama anamorphot 1.5 - 36" printed on it) on the inside of the 72mm thread. as you twist it, it unthreads from the same thread as you would attach diopters. you cannot physically grasp the ring due to it being recessed into the thread so you need to press against it while trying to twist it at the same time - in the same direction you would untwist a diopter from the 72mm thread.

QuickHitRecord had to use some rubber gloves in order to allow him to spin the ring - otherwise there isnt enough friction. mine came away slowly by hand, but it would have been quicker if I had used some rubber gloves. Make sure you mask off the front element with some masking tape to be sure you dont scratch the element.

 

OK, now I get it.  Thanks for your help!  I'll try it soon.  Would the application of lubricant like WD-40 help, or would it potentially harm the optics?

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OK, now I get it.  Thanks for your help!  I'll try it soon.  Would the application of lubricant like WD-40 help, or would it potentially harm the optics?

 

 

NO!!  don't do it.  do it dry.  with rubber gloves if it is tight.  wd-40 is NOT for lenses:)  

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I thought not, but the ring IS tight.  I'll go buy the rubber gloves.  Thanks!

 

 

yes.  don't force it if it wont move without rubber gloves.  And once the ring has started to spin, make sure you dont apply too much pressure to it.  - it's not metal, the ring is plastic so might snap if you use excess force.  the rubber gloves mean you dont have to put as much pressure on the ring.

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if it still doesnt want to budge, use some lens cleaner fluid (high alcohol content) - like Calotherm / Caloclear spray.  If you apply enough so the cleaner can seep a little between the ring and the front element (by capillary action) it wont evaporate as quickly and as it pools between the two surpaces might help to break the friction grip between the glass and the rubber seal that sits between the glass and the plastic ring.  obviously you'll have to wait for it to evaporate from the ring so you can grip onto it.  The lens cleaner might offer a degree of lubrication too and wont leave residue once it evaporates.  

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Thanks for the info to my question folks : ) I'm not sure I have the balls to do this mod [at the moment anyway] But I was wondering if there is any possibility of freeing up the 'tight' focusing action at the same time as doing this mod - or do you need to be a qualified lens tech to go any further into dissassembly?     

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Thanks for the info to my question folks : ) I'm not sure I have the balls to do this mod [at the moment anyway] But I was wondering if there is any possibility of freeing up the 'tight' focusing action at the same time as doing this mod - or do you need to be a qualified lens tech to go any further into dissassembly?     

 

 

indeed you could try.  and I doubt it would be very hard either.  it would be a case of carefully unwinding the front element past the maximum - I accidentally did this while I was doing my modification.  if you twist the focus much more than a whole turn it comes right off.  

 

You will need a very careful hand to make sure you dont damage the very tight thread when unscrewing and putting it back together.

 

 

then I would look at carefully cleaning off the grease off the male thread (on the part that comes out (which holds the front element), - you'll have to research what type of de-greaser to use.  but dont use a spray application.  you would want to spray into a lint free cloth and just use the cloth on the thread.  a piece of an old 100% cotton t-shirt would be good.  then re apply with a similar type of grease and then re-assemble.  see if this helps.  if it is still tight you might have to do the same to the female thread which will be harder to get to.  I imagine the new grease on the male thread will work into the old dried up grease on the female part and after time will loosen up nicely.  

 

While you are in there doing the focus mod, you are only 1 step away from being able to get to the dried up grease/dirt build up which is causing the tight focus ring turning.  If you feel you can unscrew/rescrew it back toghether without dmaging the thread then go for it!  I managed.

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